Safety elevator mechanism.



H. O. BARNES. SAFETY ELEVATOR MECHANISM. APPLICATION FILED EBB. 1a,1909.

931,175. Patented Aug.17,-1909.

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H. 0. BARNES.

SAFETY ELEVATOR MECHANISM.

APPLICATION FILED 313.18, 1909.

931,175. Patented Aug. 17, 1909.

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UNITED STATES HARRY O. BARNES, OF LANSING, MICHIGAN.

SAFETY ELEVATOR MECHANISM.

Specification of Letters Patent.

Patented Aug. 17, 1909.

Application filed February 18, 1909. Serial No. 478,630.

To cI ZZ whom it may concern:

lie it known that I, HARRY O. BARNES, a citizen of the United States,residing at Lansing, in the county of fnghani and State of Michigan,have invented certain new and useful improvements in Safety Elevatorlife" 1illll$i11l,()f which the following is a speci i'ication.

The object of this invention is to provide a simple, cheap, ande'liicient automatic safety elevator device for ele aters to sound analarm when one of the shaft doors is accidentally left open, and to thisend the invention consists in providing two electrical circults soarranged that when the circuit of least resistance is broken the currentwill pass through the other circuit and sound the aim in, suitabledevices being provided upon each shaft door and upon the car for makingand breaking the circuit so arranged that the opening of a door willbreak the circuit and the stopping of the car at a landing will make thecircuit, and thus prevent the sound- 'ng of the alarm when the car is inposition before a door and the door is opened. if the car is moved froma landing without the door being closed the circuit will remain open andthe alarm will be continuously sounded until the car is returned to thelanding or the door closed.

'ihe invention is carried out substantially as hereinafter descril edand shown in the accompanying drawing in which,

Figure 1 is a vertical section through an elevator well, a car orelevator cage being shown in vertical section therein; Fig. 2 is adiagrammatic view illustrating the electrical circuits and severalcontacts carried by the doors and car; and Fig. 3 is a similar viewshowing the modified form of contacts.

in the drawings the numeral 1 denotes the elevator shaft or well, 2 acar or cage, and 3 the elevator shaft doors indicated at the severallioors or landings 4:, 5, and 6. These parts are all constructed andarranged in the usual manner, the cage being provided with a dooropening to register with the doors 3 at the different landings. A closedor main electrical circuit 7 is provided in which is a battery 8 orother source of electrical energy and a bell 9 or other suitable alarm,the bat tery and alarm being located in any convenient position. A shuntcircuit 10 is connected across the main closed circuit 7 in such a waythat the current from the battery will pass through the shunt circuitwhen said circuit is closed instead of passing through the entirecircuit 7 and causing the alarm to sound. The shunt circuit is providedadjacent to the shaft doors with separated contacts 11 and 12 which areadapted to be connected and the circuit thus closed by a contact stripor plate 13 on the car, said contact strip engaging the contacts 11 and12 when the car is in position at one of the landin s to discharge ortake on a load. Each of the doors 3 is provided with a strip 1% havingcontact points 15 and 10 at its ends to engage the contacts 11 and 12when the door closed and close the circuit.

As before described when the car is stopped at a landing in properposition to take on or discharge its load, the contact strip 13 carriedby the car engages the contacts 11 and 12 in the shunt circuit 10 atthat landing, and therefore when the door 3 at that landing is opened,the contact strip 14 on the door moving with it out of contact position,the circuit will not be broken and the alarm will not be sounded by theopening of the door. lint should the door be accidentally left open andthe car moved from that landing, as shown in dotted lines Fig. 2 thuscarrying the contact strip 13 out of engagement with the contacts, theshunt circuit will be broken and the current will then pass through thealarm and cause it to sound until the door which was left open is closedand the shunt circuit thus closed, or the car moved back to that landingand the shunt circuit closed by the contact strip 13 on the car.

If desired the contacts of the shunt circuit may be formed as shown inFig. 3, in which short contacts 17 and 18 are secured to the wall of theelevator well adjacent to each loor 3, the contact 18 being a springmember which is adapted to be pressed into engagement with the contact17 to make the circuit. The circuit is closed by each door by aprojection or contact 19 on the door engaging the contact 18 and forcingit into engagement with the contact 17 when the door is closed, and thecircuit is closed at each landing by a projecting contact device 20 onthe elevator car adapted to engage the contact 18 when the car is inposition at a landing, as shown in Fig. 3 at landing 5. \"Vhen the caris moved from the landing without the well. door being closed the shuntcircuit is opened as the contact 18 will spring away from the contact 17owing to the fact that it is not held by either door or car.

By the described construction a very sim ple arrangement of wiring issecured and the contact device carried by the car and doors is also verycheap and slmple 1n construc- Having thus fully described my inventionwhat I claim is:

1. A safety elevator mechanism comprising a main electric circuit, analarm in said circuit, a shunt circuit to cut out the alarm, an elevatorcar, means carried by said car to open and close the shunt circuit,doors, and means carried by said doors to open and close the shuntcircuit.

2. A safety elevator mechanism comprising a main electric circuit, analarm in said circuit, a shunt circuit provided with contacts, anelevator car, means carried by said car to close the shunt circuit whenthe car is at a given landing, a door, and means carried by said door atsaid landing to close the shunt circuit when said door is closed.

3. A. safetyelevator mechanism comprising a main electric circuit, analarm in said circuit, a shunt circuit provided with contacts, anelevator car, a contact carried by said our to close the shunt circuitwhen the car is at a given landing, doors, and a contact carried by thedoor at each landing to close the shunt circuit when said door isclosed. I

4. A safety elevator mechanism comprising a main electric circuit, analarm in said circuit, a shunt circuit to cut out said alarm andincluding contacts at each elevator landing, an elevator car, meanscarried by said car to close the shunt circuit through said contactswhen the car is at a given landing, doors, and means carried by thedoors at the several landings to close the shunt circuit through thecontacts of the shunt circuit when said doors are closed, the shuntcircuit being opened when the car has left a given landing and the dooris left ajar.

5. A safety elevator mechanism comprising a closed main electricalcircuit, an alarm in said circuit, a shunt circuit to cut out said alarmand including separated contact points at each landing, an elevator car,a device carried by said car to close the shuntcircuit through saidcontact points when the car is at a given landing, doors, and a devicecarried by each door at each landing to close the shunt circuit throughsaid contact points when the doors are closed.

6. Safety elevator niachanism comprising a closed main electric circuit,an alarm in said circuit, ashunt circuit to cut out the alarm when saidshunt is closed and including separate contacts projecting into theelevator well at each landing, an eleator car, a contact device carriedby said car to engage said contacts and close the shunt circuit toprevent the sounding of the alarm when the car is at a given landing,well doors, a contact device carried by a well door at each landing toclose the shunt circuit through the corresponding contacts at thelandings when the doors are closed.

7. A safety elevator mechanism comprising a main electric circuit, analarm in said circuit, a shunt circuit to cut out the alarm. and meanswithin the shunt circuit to make and break said circuit adapted to beoperated by an elevator shaft door and by an elevator car.

In testimony whereof I aflix my signature in presence of two witnesses.

HARRY O. BARNES.

\Vi-tnesses GHANCEY A. Bannns, VILLIAM T. SHAW.

